This invention generally relates to the inspection of glass containers. More particularly, this invention relates to the inspection of glass containers by a device which indexes glass containers from one inspection station to another. Specifically, this invention relates to an improvement in an inspection device of the type described which allows stable rotation during inspection of flask-type glass containers.
The inspection of glass containers is now frequently carried out by indexing-type devices which use multi-pocketed starwheels to move glass containers from inspection station to inspection station. One commonly used device is the FP machine sold by Owens-Illinois, Inc. There are numerous U.S. patents illustrating this machine, one example being U.S. Pat. No. 3,313,409. This machine requires rotation of the container under inspection at some stations. This is not a problem with round or at least generally round containers. In the past, it has not been possible to use FP type machines to inspect glass containers that may broadly be defined as flask-type glass containers. These are containers which have a relatively long neck portion and a flattened main body portion. Many containers for salad dressing are also of this same general type, although they are not usually referred to as flasks; however, the term "flask" will be used herein as a generic term which includes salad dressing containers. The problem with flask-type containers is that their lack of omni-directional symmetry made them extremely difficult to rotate in a stable mode. The finish portions tended to wobble during rotation, thus leading to inaccurate inspection. We have devised a handling system for FP type inspection machines that allows rotation of flask-type glass containers in a stable manner. The neck of the container is held in a neck holder, carried by a starwheel, and has about 180.degree. of its circumference in contact with the neck holder. That portion of the neck which extends beyond the neck holder is in contact with a guide rail, thereby completing a stable chucking arrangement for the neck. The body portion may then be rotated and the finish portion will not wobble during rotation. An example of the prior art may be seen in U.S. Pat. No. 3,460,669.